Typically, in automatic paint-spraying operations, it is common to employ a robot during the painting operations. The movements of the robot are controlled by a program which maps the movement of the painting robot in relation to specific points on the object to be coated. Presently, in the prior art, it is necessary to produce the movement program whereby the path to be followed by a coating unit (spray gun) in relation to the body is controlled and it is also necessary to store the various coating parameters arising for each individually selected process parameter change points. These coating parameters include, for example, the amount of paint and the pressure and amount of atomizing air and horn-air which determine the shape and strength of the coating spray. Establishing this robot path and storing this data is normally done by hand with the aid of a "Teach-in" keyboard (cf. H. J. WARNECKE, R. D. SCHRAFT "Industrieroboter," 2nd Edition 1979, pages 33-36)
Because of the large number of coating parameters necessary to obtain a satisfactory coating, this programming is tiresome and time-consuming. Further, if the program has to be subsequently changed, for example because certain locations upon the body are not properly coated, special problems arise. In this case, because of the many paint-impingement points selected, it is very difficult with prior art methods to find the data pertaining to a specific location on the body in the stored program. In fact, up until now, it has been impossible for the programmer to associate the actual process parameter change points on the body with the stored parameters. Therefore, whenever the program had to be changed, the programmer had to move the spray gun along the robot path opposite the body to be coated step-by-step, following the program.
Since it is necessary to control not only the movement of the robot, but also additional parameters, such as horn-air, atomizing air, and the amount of paint used for the coating, prior art methods have other disadvantages. For example, according to the methods presently practiced to obtain uniform coating of differently shaped details of a body, either the robot is moved at a constant speed and the amount of paint discharged and other parameters are controlled, or the speed of the robot only is varied. In the latter case, the robot is required to move at very high speeds. If it is desired to obtain uniform coating thickness on all body details, speeds in excess of 1.5 m/sec are required at certain locations. As a result of delays in the accelerating phases and other restrictions in present-day robot systems resulting in a maximum track velocity of 1.5 m/sec, programming and optimizing are very time-consuming. However, a certain amount of adaptation is possible by varying the distance between the spraying unit and the part to be coated, with little or no structural differences in the surface of the paint. Moreover, if the same objects are to be coated with different coloring materials, appropriate changes in the movements along the robot track must be carried out for each material. Thus, if the same objects are to be coated with different paints, it has been necessary to draw different movement programs, which means considerable expenditure on programming.